772 SOME NEW AND FARE HYDROIDA IN THE AUSTRALIAN MUSEUM, 



THUIARIA SINUOSA, n.sp. 



(Plate XVIII., figs. 9-10). 



Hydrocaulus pinnate, stem indistinctly and irregularly jointed, 

 fascicled below ; pinnae alternate, with few or no joints, three 

 hydrothecse between every two on the same side of the stem. 

 HydrothecsB opposite to alternate on the pinnse, alternate on the 

 stem, a rather wide space between the two series ; long, sub- 

 conical , each one curved first slightly outwards and then upwards, 

 the extreme summit again curved outwards, adnate in their lower 

 half to the hydrocaulus, and in their upper half to the next 

 hydrotheca above, which they overlap ; a conspicuous triangular 

 area below the base of each ; aperture small, semi-circular, looking 

 directly outwards. 



Gonothecae borne in rows along the front of the pinnae, obovate, 

 with distinct transverse annulations, aperture large, margin 

 elevated : a few long crooked teeth or spines inside the neck. 



Hab.Port Molle. 



I received a small piece taken from a specimen in the Museum, 

 which, Mr. Whitelegge informs me, is about two inches high, and 

 incomplete. The species is allied in some respects to T. fenestrata, 

 but the peculiar form and arrangement of the calycles distinguish 

 it from all other known species. The stem has few joints and 

 those indistinct ; the shortest internode has two hydrotheca on the 

 same side as the pinna (which springs from between them and is 

 in contact with both), and a single one on the opposite side. The 

 longer internodes are equivalent to two or more of these with the 

 joints obliterated. The shorter pinnae in my specimen were with- 

 out joints, the longer ones had a single joint not far from the end. 

 There is a thinning away of the perisarc over the triangular spaces 

 below the hydrothecse, very much as in T. fenestrata. 



THUIARIA QUADRIDENS, Bale. 

 A slender variety, from near Peel Island, Moreton Bay. 



